<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>函数的调用</title>
</head>
<body>
            <script>
                $();
                function $() {
                 //   alert('haha');           //只执行，不返回值
            print('haha');                   //打印纸张的界面和功能
                }
            </script>
</body>
</html>